Abstract

Tofu is one ofthe most popular soya products and is prepared via coagulation ofsoya milk. The proximate composition (moisture, crude protein, crude fibre, fat, ash, carbohydrate and energy), mineral content (calcium, iron, magnesium, potassium and sodium), antinutrients (phytate, oxalates, tannins, saponins and phenols) and the sensory evaluation (colour, taste, flavour, acceptability and texture) were investigated. The moisture content ofthe fresh tofu was very high 82.42%, it reduced to 30.17% when steamed and further to 26.23% when microwaved. The crude protein ofthe fresh tofu was 8.02% which increased to 9.88% when steamed and 9.71% when microwaved. The fat content ofthe fresh tofu was 4.74% and increased to 5.17% when steamed and further increased to 5.40% when microwaved. The ash content of fresh tofu was 0.97% which increased to 2.77% when steamed and 1.62% when microwaved. The crude fibre of the fresh tofu was 0.19% and increased to 1.03 when steamed and further increased to 0.91 when microwaved. The carbohydrate and gross energy contents of the fresh tofu was 3.69% and 89.40% and further increased to 50.99% and 289.99% when steamed and increased to 56.15% and 311.98% when microwaved, respectively. The calcium content ofthe fresh tofu (105.23 mg/lOOg) was significantly (p < 0.05) higher when compared with the steamed tofu (104.54 mg/lOOg) and microwaved tofu (104.83 mg/lOOg). The iron, magnesium, potassium and sodium content 8.72, 108.04, 69.91 and 3.10 respectively of the fresh tofu were significantly (p < 0.05) higher when compared with the steamed tofu (8.02, 107.33, 69.23 and 3.02 respectively) and microwaved tofu (7.71, 105.75, 68.48 and 2.93 respectively). The phytates (0.94 mg/lOOg), oxalates (0.72 mg/lOOg), tannins (1.47 mg/lOOg), saponins (0.64 mg/lOOg) and phenols (1.01 mg/lOOg) content of the fresh tofu was significantly (p < 0.05) higher when compared with the steamed (0.72, 0.62, 1.37, 0.59 and 0.88 mg/lOOg respectively) and microwaved tofu (0.81, 0.65, 1.31, 0.54 and 0.78 mg/lOOg respectively). In the sensoruy evaluation, the colour, taste, flavor, texture and acceptability properties ofthe microwaved tofu were preferred when compared to the steamed tofu, but not preferred to the control (chicken). In conclusion, the microwaved tofu has a better sensory evaluation than the steamed tofu.